A nightmarish tale of unparalleled child abuse has come to light in Australia.

The Children’s Court has published documents about a clan that practiced incest for generations. The Daily Telegraphreports that the activities of the Colt family (a court-appointed pseudonym) were discovered in 2012, as authorities investigated a tip-off that there were children in a remote New South Wales valley who didn’t go to school. Police and community-services officers found 40 adults and children living in a squalid camp of caravans, tents and sheds, without any access to water.

The children were dirty and shy, and few were capable of intelligible speech. Many seemed developmentally delayed and malnourished. Some had oddly shaped features later found to have stemmed from inbreeding. The concept of personal hygiene was unknown.

Tests have revealed that the family members are all products of intimate relations among themselves, and that children began having sex with each other at a young age. One woman in all likeliness birthed both her father’s and brother’s children.

The clan’s origin may date back to a set of great-great-grandparents, who were brother and sister. The Colts apparently moved frequently, possibly in order to evade detection. In a village near where they last set up camp, it was a common joke that people living in that area of the valley must be inbred, but the villagers never fathomed the family’s dark secret.

Some of the children have now been placed with foster families, while others are in treatment programs for sexualized behavior and psychological trauma. The mothers vary in their acceptance of responsibility. The Children’s Court ruled that a mother of 13 children was found “incapable of addressing her own traumatic history.”